body{
    background-image: url("../img/学校风景1.jpg");
    background-position: center center;
    background-repeat: no-repeat;
    background-attachment: fixed;
    background-size: cover;
}
.login{
    margin-top: 200px;
    width: 400px;
    height: 280px;
    margin: auto;
    background-color:#96B1E2;

}